[Cystadenocarcinoma complicating urachal cysts. A case report and review of the literature (author's transl)].

A 50-year-old man developed a cystadenocarcinoma on a large urachal cyst. Only 15 similar cases have been reported in the published literature, equivalent to less than 10 p. cent of cancers of the urachus. These tumours present certain clinical, radiological, endoscopic, ultrasonographic, and pathological characteristics. As against solid urachal tumours, there is little controversy as to their vestigial origin from the remains of the allantoid canal. Their prognosis is poor, regional recurrences and pulmonary metastases, and complicated or uncomplicated urachal cysts should therefore be systematically excised.